Methyl salicylate treatments of sweet cherry trees improve fruit quality at harvest and during storage

Abstract

The aim of this work was to evaluate the effect of methyl salicylate (MeSA) treatments of sweet cherry trees on fruit quality properties at harvest time and during cold storage. Experiments were performed during two consecutive years by using two cultivars, ‘Sweet Heart’ and ‘Sweet Late’ in 2013, and three cultivars, ‘Sweet Heart’, ‘Sweet Late’ and ‘Lapins’ in 2014. In the 2013 experiments, three MeSA concentrations (0.5, 1 and 2mM) were applied at three key points of on-tree fruit development and results showed that the 1mM concentration was the most appropriate in terms of increasing fruit size and quality parameters (improved colour, firmness and total soluble solids) at the time of harvest. Sensory analysis revealed that appearance, firmness and sweetness scores were higher in 1mM MeSA treated cherries than in the control ones. Thus, 1mM concentration was chosen for the 2014 experiments, in which it was found that MeSA treatments did not affect total fruit yield. The fruits from both control and 1mM MeSA treated trees was stored at 2°C and a relative humidity (RH) of 85% for 28 days and results showed that preharvest MeSA treatments delayed the postharvest ripening process, manifested by a lower degree in colour changes, and less loss of acidity and firmness in treated fruits with respect to controls, leading to maintenance of fruit quality. Overall, preharvest treatments with 1mM MeSA at three key dates of sweet cherry growth and ripening improved fruit quality attributes at the time of harvest and after postharvest storage, showing that MeSA could be a safe and environmentally friendly tool with potential practical application to improve sweet cherry fruit quality.